Recycling contamination is measured differently across communities, states, and material recovery facilities (MRFs). In the 2020 State of Curbside Recycling Report, only about 35% of communities knew their inbound contamination rate, and those communities reported an average of 16.9%. State-level research also shows wide variation: average single-family inbound contamination was 20% in California, 11% in Oregon, and 9% in Washington.
Table of contents
- How contamination is measured
- Community contamination rates
- State comparisons
- Education, participation, and enforcement
- What MRF acceptance data shows
- National recycling measurement gaps
How contamination is measured
Inbound contamination refers to material entering a recycling stream that should not be there or cannot be processed in that system. A related measure is the MRF residual rate, which captures material left over after sorting and processing. These measures are useful, but they are not interchangeable: an inbound rate describes what arrives, while a residual rate describes what remains after processing.
The Recycling Partnership’s 2020 State of Curbside Recycling Report found that only about 35% of communities knew their inbound contamination rate. Among communities that knew the figure, the average inbound contamination rate was 16.9%. Measurement methods were uneven: 57% obtained the information from periodic MRF audits, while nearly 15% received data from an MRF covering all communities sending material to that facility.
Program design was associated with a measurable difference in the same report. Bin- or bag-based recycling programs had inbound contamination rates about 5 percentage points lower than cart-based programs. This is a comparison between program types, not a universal result for every community.
The U.S. Environmental Protection Agency (EPA) includes contamination in its national recycling metrics alongside recycling performance, processing efficiency, and recycled-material markets. That framework recognizes that a recycling rate alone does not describe how much material is rejected or how efficiently a system operates.
Community contamination rates
The available community data shows why a single national contamination number can be misleading. Communities differ in accepted materials, collection containers, education, measurement methods, and the MRF receiving the material. Even where communities know their rate, the figure may come from a periodic audit rather than continuous measurement.
The 16.9% average reported by communities that knew their inbound rate is therefore best read as a reported average for that surveyed group. It is not a nationwide estimate for every U.S. recycling program. The finding that about 35% of communities knew their rate also means that a majority did not report having that measurement.
The source reported two main information channels. Periodic MRF audits supplied data for 57% of communities that knew their inbound rate. Nearly 15% used data from an MRF that covered all communities going to that facility. These percentages describe how communities obtained contamination information, not the share of all communities with audited material.
The report also compared collection formats. Bin- or bag-based programs recorded inbound contamination rates about 5 percentage points lower than cart-based programs. The comparison suggests that container and collection design can coincide with different contamination outcomes, but it does not establish that container type alone caused the difference.
State comparisons
The Recycling Partnership’s West Coast Contamination Initiative Research Report Addendum reported single-family inbound contamination ranges and averages for California, Oregon, and Washington. The results show both geographic differences and substantial variation within states.
| State | Single-family inbound contamination range | Average single-family inbound contamination | MRF residual range | Average MRF residual |
|---|---|---|---|---|
| California | 8%–46% | 20% | 5%–36% | 19% |
| Oregon | 9%–15% | 11% | Not reported in the supplied figures | Not reported in the supplied figures |
| Washington | 5%–20% | 9% | 6%–15% | 11% |
California had the highest reported average single-family inbound contamination among the three states at 20%, compared with 11% in Oregon and 9% in Washington. California’s range, from 8% to 46%, was also much wider than Oregon’s 9% to 15% range and Washington’s 5% to 20% range.
The same addendum reported California MRF residual rates from 5% to 36%, with an average of 19%. Washington’s MRF residual rates ranged from 6% to 15%, with an average of 11%. These residual figures describe the surveyed MRF results and should not be treated as direct substitutes for household inbound contamination.
The state results also show why averages should be paired with ranges. A California average of 20% includes facilities or communities at both 8% and 46%. Washington’s 9% average includes reported results from 5% to 20%. A single average can conceal the operational spread that local programs need to understand.
Education, participation, and enforcement
The addendum reported participation and education spending for California, Oregon, and Washington single-family programs. California participation ranged from 64% to 95%, with an average of 87%. Education budgets ranged from $0.10 to $6.27 per household in California, $0.03 to $6.93 in Oregon, and $0.06 to $6.30 in Washington.
Average education spending was $2.34 per household in both California and Oregon. Washington reported a higher average of $3.58 per household. These are reported budget figures, not a test of the amount required to reduce contamination by a particular percentage.
California city responses also documented contamination education and enforcement activity. Eighty-four communities reported contamination education, while 50 reported no contamination education. Forty-two communities had recently completed an anti-contamination campaign, three had a campaign planned for the future, and 10 had no anti-contamination campaign planned or completed. California cities issued fines for contaminated carts in 29 communities.
The same California survey reported 173 multifamily recycling programs. Of the responding cities, 122 offered multifamily recycling technical assistance and 48 did not. It also recorded 129 cities with resident drop-off recycling programs and 47 without them. These counts describe the survey responses and are not a complete census of every California city.
Participation and education are related system measures, but the supplied figures do not quantify a causal relationship between education budgets, campaigns, fines, and contamination rates. They do show that programs used different combinations of education, technical assistance, drop-off access, and enforcement.
What MRF acceptance data shows
The addendum survey counted 80 California MRFs handling residential materials and received 54 California MRF responses, a 68% response rate. Oregon had seven MRFs handling residential materials and six responses, an 86% response rate. Washington had 11 MRFs and seven responses, a 64% response rate.
California’s responses also show that accepted materials varied considerably across facilities. The number of California MRFs accepting each material was:
- Cartons: 22 facilities; cold cups: 8; hard-cover books: 24; hot cups: 4.
- Ice cream containers: 10; mail: 51; kraft bags: 36; magazines: 51.
- Newspapers: 53; old corrugated containers: 54; office paper: 54; paperback books: 46.
- Paperboard boxes: 51; pizza boxes: 25; shredded paper: 42; tissue paper: 15.
- Bottles and jars: 54; drinking glass: 19; aerosol cans: 34; steel cans: 54.
- Foil or foil-like containers: 45 facilities.
These counts are important for interpreting contamination: an item can be recyclable in one local program but unacceptable in another. For example, the survey recorded 54 facilities accepting old corrugated containers, office paper, bottles and jars, and steel cans, but only four accepting hot cups and eight accepting cold cups. Acceptance counts do not measure contamination directly, but they help explain why local instructions matter.
National recycling measurement gaps
EPA’s U.S. Recycling Infrastructure Assessment and State Data Collection Reports identified major gaps in state and territory data collection. About 50% of states and territories collected data on the number of community curbside recycling programs, while just over 60% collected data on the number of drop-off programs. Eighty percent did not have deposit programs.
Among states and territories with deposit programs, two thirds collected data on residential packaging collected through those programs. Only 15% collected data on capture rates for community recycling programs. Eighty-eight percent did not collect data on the types of single-use plastics currently in commerce.
About 50% of states and territories measured an overall recycling rate. The average recycling rate estimate reported by states and territories was roughly 30%. EPA separately says the current U.S. recycling rate is 32% and has set a national recycling goal of 50% by 2030 in its National Recycling Goal: Recycling Rate Measurement materials.
EPA also received letters from 61 unique commenters containing more than 800 individual comments on national recycling measurement. The participation figures indicate substantial interest in measurement, while the state and territory collection figures show that important data remains incomplete.
EPA’s infrastructure assessment estimated that $36.5 billion to $43.4 billion would be needed to modernize U.S. recycling infrastructure. EPA said that investment could recover an additional 82 million to 89 million tons of packaging and organic waste. The agency described that amount as a 91% increase over the estimated 94 million tons recycled and composted in its 2018 Facts and Figures report, and said the national recycling rate could rise from 32% to 61% with those investments.
Those investment and recovery figures are EPA estimates, not measurements of contamination already removed. The 2018 baseline is a legacy figure identified by EPA, and the projected increase is a forecast tied to the stated infrastructure investment scenario.
Sources and measurement context
The national measurement and investment figures come from the U.S. Environmental Protection Agency’s National Recycling Goal: Recycling Rate Measurement and U.S. Recycling Infrastructure Assessment and State Data Collection Reports. Community contamination findings come from The Recycling Partnership’s 2020 State of Curbside Recycling Report. West Coast state, program, MRF, and material-acceptance figures come from The Recycling Partnership’s West Coast Contamination Initiative Research Report Addendum.
Because the sources use different populations, dates, geographies, and definitions, the figures should be compared only within their stated context. The clearest pattern is not one universal contamination rate, but uneven measurement combined with wide local and state variation.